Centrifugal liquid-separator.



PAT ENTED JAN. '13, 1903.

0. A. & 0. W. HULT. GENTRIPUGAL LIQUID SEPARATOR.

APPLICATION FILED SEPT. 8, 1902.

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H0 MODEL.

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No. 718,461. Q PATENTED JAN. 13, 1903. 0. A. & 0. W. HULT.

GENTRIFUGAL LIQUID SEPARATOR.

Arrmonloy IILE'D snrzr. 8, 1902. l i no MODEL. i 2 SHEETS-SHEET 2.

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- NITE STATES 'AJTENT GFFICE.

CARL ALRIK HULT AND OSCAR WALFRID HULT, OF STOGKHOLM, SWEDEN.

SPECIFICATION forming part of Letters Patent No. 718,461, dated January 13, 1903,

Application filed September 8, 1902. Serial No. 122,625. (No model.)

To all whom it may concern;

Be it known that we, CARL ALRIK HULT, of Flemminggatan 48, and OSCAR WALFRID HULT, of Handtverkaregatan 30, Stockholm, in the Kingdom of Sweden, have invented vcertain new and useful Improvements in Gentrifugal Liquid-Separators, of which the following is a specification, reference being had therein to the accompanying drawings.

Centrifugal liquid-separators turned by hand and of the construction hitherto embined with a float and situated below the said vessel for the purpose of causing the liquid to leave the vessel in a constant current independent of the height of the liquid in the vessel. In separators of the said type it happens that the rotary velocity of the drum,dependent on the velocity of the crank, is not continuously proportioned to the quantity of liquid entering the drum, the said disadvantage being due to irregular turning of the crank and resulting in a bad and irregular separation. This fault, especially existing in centrifugal separatorsv turned by hand, has given rise to the opinion that the said separators are not so suitable for the separation of liquids--such, for instance, as milkas centrifugal separators driven by a motor. When turning a crank by hand continuously for a long time, more especially when great strength is exerted, the velocity will vary very considerably, especially if the turning of the crank is interrupted for supplying the vessel with milk, as is the case in existing centrifugal separators turned by hand.

This invention relates to means for separating milk or other liquids of diiferent specific gravity in such a manner that during the separating operation the centrifugal force or the rotary velocity of the drum will be proportioned to the quantity of liquid supplied to the drum, or, vice versa, the quantity of liquid supplied to the drum will be proportioned to the rotary velocity of the crank.

This object is attained by effecting the said supply of milk or liquid by means of a suction and force pump connected with a rotating part of the centrifugal separator in such a manner that the velocity of the same is constant in relation to the velocity of the drum, the velocity of the liquid entering the drum being controlled not by the said pump directly, but by the liquid-pressure in a tube, vessel, or the like communicating with the pump and delivering the liquid to the drum through a bottom opening, the said pressure being controlled by the velocity of the pump. The said tube or vessel being provided with a scale empirically graduated or with marks the liquid-pressure can easily be observed by the person turning the separator and the number of revolutions can easily be read off. Consequently in a centrifugal separator constructed in accordance with this invention the useful effect need not be limited to a certain quantity per unit of time, as is the case in other centrifugal sepa-. rators turned by hand, but the separator is able to operate, for example, on ten gallons by fifty revolutions, twelve gallons by sixty revolutions, fifteen gallons by eighty revolutions, or twenty gallons by one hundred revolutions of the crank, with a constant skimming capacity.

In the accompanying drawings, Figure 1 is a side view, partly in section, of a separator arranged in accordance with this invention. Fig. 2 is a vertical sectional view of the pump; and Fig. 3 is a vertical sectional view of the same, taken at right angles to the view in Fig. 2.

As usual, the centrifugal separator consists of a drum and the necessary vessels for receiving the separated liquids of different weight and with a motion-transmittin g device for efiecting the necessary-rotation of the drum. To the main shaft of the said device a crank 1 is fixed. A suction and force pump 2 is mounted near the said crank and in the frame of the separator, the said pump being I acted upon by the crank. The pump-cylinder has a suction-pipe 3 and a delivery-pipe 4, the latter leading to a vessel 5, provided with a gage-glass and a scale 6 empirically graduated for indicating the amount of the supply of liquid to the separator,the said sup- IOO ply being dependent on the velocity of the crank. From the bottom of the said vessel 5 a discharge-pipe 7 leads into the drum B,which is rotated upon the said pipe 7, which serves as a stationary pivot-pin. 9 indicates a receptacle for the liquid to be treated. The said pump consists of a cylinder 2, fixed to the frame of the separator by means of a screw or the like, so as to be detached from the same, and of a piston 12, pressed against a cam 14, provided on the crank-shaft or the crank, by a spring 15, mounted between the inner end of the piston and the closed end of the cylinder 2, the said piston being provided with a roller13, bearing against the said cam at the open end of the cylinder. The pump is provided with valves, preferably ballvalves, as shown in the drawings, or valves of any other suitable construction.

The object of the construction of the pump described above is to facilitate the disconnection of its parts when the same are to be cleaned. It will be seen that the cylinder and the piston are free to separate as soon as the cylinder is removed from the frame of the separator, the said two members being thus easy of access. In the drawings the cam 14 has a triangular shape for effecting three strokes of the piston during one revolution of the crank in order that the supply of liquid may be substantially uniform and to allow of the employment of a pump provided with a short cylinder. The said cam may, however, have an ordinary eccentric shape or be provided with a greater number of faces than that shown in the drawings. The said cam only moves the piston outward from the center of the crank-shaft, the return stroke being effected by the pressure of the spring 15. By this arrangement means for connecting the piston with the crank or the operating part can be dispensed with, the hereinbefore mentioned facility of disconnecting the parts of the pump being thus afforded. The said driving mechanism may be modified by providing the piston with an eccentric in place of the roller 13 and the crank-shaft with a circular disk, turning the said eccentric by friction. By employing a disk which is three times as large as the said eccentric the same result will be attained as in the case stated above. The roller 13 is provided with a'fiange for preventing the piston 12 from rotating. The said pump may be provided with an ordinary airchamber for causing a uniform supply of liquid.

The operation of the above-described device is as follows: The liquid (preferably the whole quantity to be treated) is poured into the vessel 9. \Vhen the crank is turned, the pump will begin to raise milk from the vessel 9 through the pipe 3 and deliver the same into the vessel 5 through the pipe 4:, the centrifugal drum being at the same time set in motion. The outlet-pipe 7 in the bottom of the vessel 5 is somewhat narrower than the pipe 4, in consequence whereof liquid will remain in the vessel 6 and cause pressure. Owing to this pressure, the velocity of the current passing through the pipe 7 is increased, so that the quantity of liquid passing into the vessel during a unit of time is equal to the quantity of liquid leaving the same. If the velocity of the crank be increased, the equilibrium will be destroyed, so that the pressure of liquid in the vessel 5 is increased until the velocity of the liquid leaving the vessel (which velocity is increased by the said increased pressure) counterbalances the increased quantity of liquid passing into the same, the equilibrium being thus restored. Thus a comparatively great liquid-pressure will correspond to a comparatively great velocity of the crank.

In order to further illustrate the invention, lines a, b, c, d are shown in Fig. 1, representing the scale. If the pressure indicated by the lowest line a corresponds to the treatment of twenty-five gallons at a velocity of fortyfive revolutions of the crank, the second line b may correspond to twenty-eight gallons at a velocity of fifty revolutions, the third line 0 may correspond to thirty gallons at a velocity of fifty-five revolutions, and the fourth line (Z may correspond to thirty-three gallons at a velocity of sixty revolutions. On the other hand, the revolutions of the crank can be ascertained from the height of liquid. A graduated pipe may be substituted for the vessel 5, Fig. 1, the pipe 4 being then placed in communication with the said graduated pipe through a hole provided in the wall of the same, as indicated by the dotted lines 11 in the said figure. Thus it will be seen from the above that the supply of liquid to the drum 8 is altered in a definite proportion to the velocity of the pump and the drum. The vessel 5 will act at the same time as a regulator or a device for adjusting any irregular pressure of liquid caused by the pump when the same delivers a variable current during the revolution of the stroke. The pump may be of any known typefor example, it may be a rotary pump, a pump provided with reciprocating piston, a pump provided with one or more cylinders, or a suction and force pumpwithout departing from the principle of our invention.

The vessel or pipe 5 can, if required, be dispensed with, in which case the pump will deliver the liquid into the drum directly through the pipe 4:. It is important, however, for centrifugal hand separators that the separator and the pump shall receive motion from the same crank, the advantage being thus obtained that the velocities of the drum and the pump are always properly propor tioned to each other, although the apparatus may be driven by hand, and consequently is not provided with a special regulator.

Having now described our invention, what we claim as new, and desire to secure by Letters Patent, is

1. In a centrifugal liquid-separator the combination of the rotating drum, a shaft provided with a crank, turned by hand, means for transmitting motion from the said shaft to the drum, and a pump, also receiving its motion from the said shaft or crank and transporting the liquid from a vessel into the drum in order that the supply of liquid to the said drum always may be proportional to the velocity of the drum, substantially as described.-

2. In a centrifugal liquid-separator the combination of the rotating drum, a shaft provided with a crank to be turned by hand, means for transmitting motion from the said shaft to the drum, a pump transporting the liquid to the said rotating drum, a cam and a roller, by means of which the pn mp receives motion from the said crank or crank-shaft, substantially as described.

3. In a centrifugal liquid-separator the combination of the drum, a crank to be turned by hand, a motion-transmitting device for rotating the drum, a pump, receiving its motion from the said crank or its shaft, and a graduated vessel 5 receiving the liquid, to be treated, from the pump, and delivering the same into the drum in quantities controlled by the liquidpressure in the said vessel, which pressure is depending on the velocity of the pump, substantially as described.

4. In a centrifugal liquid-separator the combination of the rotating drum, a motiontransmitting device and a crank for turning the drum by hand, a pump for transporting the liquid, to be treated, to the said drum, the said pump being operated by the said crank or its shaft and having its casing at the one open end slipped upon the piston, acted upon by the crank-shaft or the crank by means of a cam or the like, which casing is fixed and incloses a spring, which together with the said cam reciprocates the said piston, and a vessel 5 receiving liquid from the said pump and delivering the same to the rotating drum proportionally to the velocity of the drum, substantially as described.

In witness whereof we have hereunto signed our names in the presence of two subscribing witnesses.

CARL ALRIK HULI. OSCAR WALFRID HUL'I. Witnesses:

ERNST SVANQVIST, A. F. LUNDBORG. 

